Advantages and Disadvantages of Pond Aeration

Advantages and disadvantages of pond aeration

Oxygen is elementarily important for the biological processes in the pond. The fish and other animals in the pond cannot live without oxygen. Unlike in a lake, there may not be enough oxygen in a pond. Pond aeration can compensate, but it is also controversial. In this post, you’ll learn more about the pros and cons of pond aeration and what you should consider when using it.

When You Can Do Without Pond Aeration

You can do without pond aeration if no fish are living in your pond. Even if there are fish in the pond, you don’t necessarily need to invest in a pond aerator. If you have enough plants in your pond, the amount of oxygen they produce may already be sufficient.

Pond Aeration Supports the Filter

Not only can a pond aerator provide an extra supply of oxygen, but it has other benefits as well. It supports the filter and ensures that the layers of water are well mixed. Pollution and floating algae can be better sucked in and removed by the filter. The pond pump, therefore, contributes to clean water.

In the pond filter, some bacteria clean the water. They convert ammonia into nitrite and then into nitrate. This does not work without sufficient oxygen. The bacteria reduce the oxygen content in the filter. If there is not enough oxygen, the filter processes will deteriorate in the long term. If there is a lack of oxygen, the non-toxic nitrate is converted back into nitrite. The oxygen transport in the blood of the fish is disturbed by nitrite. Your fish can die in the worst case. Pond aeration can prevent a drop in oxygen levels.

Pond aeration can support nutrient decomposition in the filter circuit and thus indirectly counteract algae formation. Even various critics, who think that pond aeration would be extra only for the oxygen supply of the fish, appreciate this benefit of the pond pump.

When You Should Use Pond Aeration

If you have no or only a few plants in the pond, as is sometimes the case with a koi pond, you should not do without pond aeration. With pond aeration, a good supply of oxygen to the fish is guaranteed. However, since other gases can also enter the water through aeration, you should check the water values regularly. The best way to do this is with a droplet test, with which you can check all water values individually. In summer, you should check the water values at least once a week.

The garden pond is a biosystem that produces oxygen through photosynthesis. It can only take place when there is sufficient light. In cloudy weather or at night, photosynthesis does not work. If photosynthesis is weak, the oxygen produced is not enough. With pond aeration, you can ensure a good supply of oxygen even then. At night, you should use a timer.

Pond Aeration in Winter

If an ice cover has formed on your pond in winter, not enough oxygen is produced anymore because photosynthesis is limited. Oxygen can no longer enter the pond from the outside. Foul gases cannot escape through the ice cover. Your pond becomes a ticking time bomb for the animals living in it. To prevent this, you should use a pond aerator. It has a double benefit: Your pond is properly oxygenated again, while the rotting gases can escape.

It is essential to have a hole in the ice cover. You should not knock the hole in the ice with a hammer or ax. You could injure the fish in the process. The pressure wave could burst the sensitive swim bladders of the fish. A better choice is an ice-freeholder with a sink chamber.

Good Oxygen Supply in Summer

A pond aerator also does an excellent job in summer. The saturation point drops as water temperatures rise. This means that as temperatures rise, less oxygen is dissolved in the water. As the fish are more active and you feed the fish, additional oxygen is needed. If there is too little oxygen, it can start a vicious cycle. Photosynthesis deteriorates. The water values become worse and worse. Your fish can no longer breathe well. If the water tilts, this means the death sentence for your fish.

It would be best if you thought of enough plants in your pond to produce enough oxygen. Once the saturation point is reached, the water can no longer absorb oxygen from the outside.

Functionality and Structure of the Pond Aeration

To use a pond aerator properly, you should know how it works. A pump pumps air through a hose into an aerator. The aerator pumps oxygen into the pond water. When it comes to pond aerators, you can choose from a variety of options. In addition to free-floating pond aerators, some models operate at the pond’s bottom and spray oxygen into the pond. The pond aerators that work at the bottom are more popular because they are not visible. They are described in this article. However, the free-floating pond aerators work similarly.

The pump of the pond aerators is available as a piston pump and a diaphragm pump. A piston pump can move large amounts of air. However, the disadvantage to the diaphragm pump is that it is noisier and also more expensive. A diaphragm pump can only deliver smaller quantities of air and is less costly. It is, therefore, more suitable for smaller ponds.

The air diffuser comes in different shapes and colors. It should pump the air bubbles into the pond water as finely as possible. The finer the air bubbles, the better the transition of the gas mixture into the water. Most often, the outlets are made of ceramic or plastic. Outlets made of ceramic are more resistant and easier to clean.

When buying a pond aerator, you should make sure that no oil is required for its operation. You should also make sure that the noise level is as low as possible.

Selection of aeration depending on the size of the pond.
Which pond aerator you should choose depends on the size of your garden pond. Furthermore, it would help if you based your choice of strength on the number of fish you have and the plants present in the pond. You should also consider the type of food and the amount fed.

As a rule of thumb, the pumping rate per hour should be approximately one-quarter of the pond volume.


You do not need pond aeration if there are no fish in your pond and enough aquatic plants. The pond aeration supports the filter because the water layers are well mixed, and algae and dirt get into the filter better. It is, therefore, a wise investment. In the winter months, when there is a blanket of ice on the pond, you can use pond aeration to ensure oxygenation. In the summer, you will prevent the water from quickly becoming cloudy. When choosing pond aeration, you should be guided by the size of the pond, the number of fish, and the plants present.

Florian Egert

I am Florian Egert, the owner of I live with my wife and two children in Germany in a small village in the countryside.

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